Sunscreen having disappearing color indicator

ABSTRACT

A colored sunscreen emulsion which enables the user to more effectively protect against skin damage, by facilitating more complete and uniform coverage of the sunscreen on the skin, comprises: 
     a) at least one oil-soluble dye that imparts a color other than white to the sunscreen, in amounts such that when the emulsion is rubbed into the skin, the color substantially disappears; 
     b) at least one sunscreen active agent in an amount effective to protect skin against the actinic radiation of the sun; 
     c) at least one emulsifier; 
     d) sufficient water to form the colored emulsion; and 
     e) optionally, one or more ingredients from one or more of the following classes: emollients, humectants, dry-feel agents, waterproofing agents, preservatives, antioxidants, chelating agents, insect repellents and fragrances.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims benefits under 35 U.S.C. § 119(e) fromprovisional application No. 60/084,180 filed on May 4, 1998.

INTRODUCTION TO THE INVENTION

The invention relates to compositions for skin application, to protectagainst the effects of ultraviolet radiation exposure.

Sunscreens are substances or compositions applied to the skin to protectthe skin from damage, such as sunburn, due to excessive exposure toultraviolet radiation. The typical commercial product is an emulsion,preferably an emulsion having a continuous (external) aqueous phase anda discontinuous (internal) oily phase; such "oil-in-water" emulsionshave a particularly pleasing feel when applied to the skin, since thesensation is one of applying an aqueous material. Most of such productsare sold in the form of lotions. When uniformly applied to the body,sunscreens can be highly effective in protecting against damage.However, less effective protection can occur when areas of the body areunevenly covered because the sunscreen is hard to see while being spreadonto the skin. Children may be at greater risk of damage than adults,since self-applied coverage on children's skin tends to be moreincomplete, uneven or inconsistent, and children tend to be less awareof their sunburn condition until it becomes serious.

PCT International Patent Application WO 94/26233 teaches thatphenolphthalein, an acid-base indicator, can be added to sunscreens tocreate a disappearing pink coloration, provided the sunscreens areformulated at a pH greater than 9.0. However, phenolphthalein can induceskin rashes and eruptions. Additionally, formulations with this pH aretoo highly alkaline and can be irritating to the skin.

PCT International Patent Application WO 95/28912 teaches composite UVsunblock compositions that may contain colored particles. However, whenthe sunscreen of WO 95/28912 is topically applied to the skin, thesunscreen remains visibly colored.

U.S. Pat. No. 5,747,011 relates to a colored sunscreen composition which"disappears" when dried on the skin or rubbed into the skin. Thecomposition incorporates water-soluble dyes, as the color formers.However, it has been discovered that some common fabrics can beindelibly stained by at least some of the dyes, when the compositioncontacts the fabrics.

Accordingly, an approach was sought to provide a colored sunscreenformulation which could be readily visualized while the sunscreen isbeing applied to the skin, but would substantially disappear when rubbedinto the skin, and which has a reduced potential for fabric staining.

SUMMARY OF INVENTION

It has been surprisingly and unexpectedly found that although theinclusion of an oil-soluble dye to a sunscreen emulsion can render thesunscreen visually colored, that such coloration will substantiallydisappear when the sunscreen emulsion is rubbed into the skin.

Thus, in one embodiment, the present invention is directed toward acolored sunscreen emulsion comprising:

a) at least one oil-soluble dye that imparts a color other than white tothe sunscreen emulsion, in amounts such that when the sunscreen emulsionis rubbed into the skin, the color substantially disappears;

b) at least one sunscreen active in an amount effective to protectagainst the actinic radiation of the sun;

c) at least one emulsifier; and

d) sufficient water to form the colored emulsion.

The amount of the oil-soluble dye in the emulsion can range from about0.0005 to about 0.5 weight percent of the emulsion, preferably fromabout 0.002 to about 0.2 weight percent of the emulsion. Also preferredis that the emulsion is an oil-in-water emulsion.

Optionally, the colored, sunscreen emulsion can contain one or moreadditional ingredients, including emollients, waterproofing agents,dry-feel modifiers, antimicrobial preservatives, insect repellentsand/or fragrances.

In another embodiment, the present invention is directed towards amethod for protecting the skin against sunburn comprising topicallyapplying the sunscreen emulsion as described above to the skin.

An advantage of the present invention is that it provides a sunscreenand a method for protecting against sunburn that enables the user toapply the sunscreen more completely and uniformly to the skin, thusproviding more effective protection against sunburn.

A second advantage of the present invention is that it provides asunscreen with a color indicator which has a low potential for indeliblystaining fabrics, when promptly cleaned therefrom.

A third advantage of the present invention is that it provides a coloredsunscreen and a method for protecting against sunburn which is moreenjoyable for children to use because of the attractiveness andappealing nature of the color indicator.

DETAILED DESCRIPTION OF THE INVENTION

In the present specification, the terms "emulsion," "formulation" and"composition" can be used interchangeably. The emulsion of the presentinvention contains one or more oil-soluble dyes, one or more sunscreenactives, one or more emulsifiers, water; and may optionally contain oneor more emollients, humectants, dry-feel agents, waterproofing agents,preservatives, antioxidants, chelating agents, insect repellents andfragrances.

Oil-Soluble Dyes

Certified dyes are synthetic organic substances which are manufacturedso that each batch passes a U.S. Food & Drug Administration (FDA) purityinspection. If approved by the FDA, these dyes are certified for use infoods, drugs, cosmetics (FD&C colors), drugs and cosmetics only (D&Ccolors), or only in topically applied drugs and cosmetics (external D&Ccolors).

Oil-soluble, certified dyes are used mostly in water resistant cosmeticproducts, including foundations and eye liners. Among the certified dyeswhich are useful in the present invention are those denoted D&C Green#6, D&C Violet #2, D&C Red #17 and D&C Yellow #11. The adopted names forthe foregoing dyes, when not certified according to FDA regulations, arerespectively: solvent green 3; solvent violet 13; solvent red 23; andsolvent yellow 33. The noncertified versions of the dyes are also usefulin the invention, where their use is legally permitted.

It is desirable to use dyes which form colors easily visualized when asunscreen-effective amount of the formulation is spread onto the skin.The more preferred colors include blue, purple, violet, yellow, greenand aqua, all of which colors contrast with the skin quite vividly. Manyappropriate colors can be produced by mixing two or more of the readilyavailable dyes, in desired proportions.

The sunscreen emulsion should contain the oil-soluble dye in an amountsufficient to enable the sunscreen to be readily visualized wheninitially applied to the skin, but in which the color substantiallydisappears when the sunscreen emulsion is rubbed into the skin. One ormore oil-soluble dyes can be employed in the composition, in an amounttotaling about 0.0005 to about 0.5% by weight of the sunscreencomposition, preferably from about 0.002 to about 0.2%, and morepreferably from about 0.01 to about 0.1%

Since the dyes are oil-soluble, they will be a part of the internalphase of an oil-in-water or water-in-oil-in-water emulsion, andtherefore will be less available to stain fabrics with which theemulsion may come in contact. Unless the emulsion is allowed tode-emulsify, such as by drying, a simple rinse or treatment with a soapsolution can remove at least most of the staining potential before thedye is incorporated into the fibers.

Sunscreen Active Ingredients

The compositions of the present invention can contain a sunscreeningeffective amount of one or more oil-soluble or water-solublesunscreening UV-B active agents or a mixture of one or more UV-B activesand one or more UV-A actives. UV-A type sunscreening actives protectagainst longer-wavelength actinic radiation of the sun in the 320 to 400nm range and UV-B type sunscreening actives protect against shorterwavelength actinic radiation of the sun in the 290-320 nm range.

Typical sunscreen actives include: aminobenzoic acid at up to about 15weight percent; cinoxate at up to about 3 weight percent; avobenzone atup to about 3 weight percent or about 2 to 3% in admixture with one ormore other sunscreen active agents; diethanolamine methoxycinnamate atup to about 10 weight percent or about 8 to 10% in admixture; digalloyltrioleate at up to about 5 weight percent or about 2 to 5% in admixture;dioxybenzone at up to about 3 weight percent alone or in admixture;ethyl 4-[bis(hydroxypropyl)]-aminobenzoate at up to about 5 weightpercent or about 1 to 5% in admixture; glyceryl aminobenzoate at up toabout 3 weight percent or about 2 to 3% in admixture; homosalate at upto about 15 weight percent or about 4 to 15% in admixture; lawsone at upto about 0.25 weight percent, together with dihydroxyacetone at up toabout 3 weight percent, alone or in admixture; menthyl anthranilate atup to about 5 weight percent or about 3.5 to 5% in admixture;octocrylene at up to about 10 weight percent or 7 to about 10% inadmixture; octyl methoxycinnamate at up to about 7.5 weight percent orabout 2 to 7.5% in admixture; octyl salicylate at up to about 5 weightpercent or about 3 to 5% in admixture; oxybenzone (benzophenone-3) at upto about 6 weight percent or about 2 to 6% in admixture; padimate O atup to about 8 weight percent or about 1.4 to 8% in admixture;phenylbenzimidazole sulfonic acid at up to about 4 weight percent orabout 1 to about 4% in admixture; red veterinary petrolatum at up toabout 100 percent or at least about 30% in admixture; sulisobenzone atup to about 10 weight percent or about 5 to 10% in admixture; titaniumdioxide at up to about 25 weight percent or about 2 to 25% in admixture;and trolamine salicylate at up to about 12 weight percent or about 5 to12% in admixture.

Typical suitable UV-B type sunscreening actives include benzophenone-3,benzophenone-8, substituted para-aminobenzoates, alkyl esters ofpara-methoxycinnamate such as octyl p-methoxycinnamate, available fromGivaudan Corp., Clifton, N.J. U.S.A. under the tradename Parsol MCX, andoctyl salicylate available from Harmann and Riemer, Springfield, N.J.U.S.A. The amount of UV-B type sunscreening active should be sufficientto give an SPF of 2 to at least 15.

Typical suitable UV-A type sunscreening actives include oxybenzone andavobenzone. Sunscreen emulsions containing mixtures of UV-B and UV-Atype sunscreen actives should be able to provide an SPF of 2 to at least50.

Except as noted otherwise, one or more sunscreen actives can be employedin the composition in amounts up to about 35 weight percent, preferablyabout 12 to about 30 weight percent of the sunscreen composition, morepreferably from about 5 to about 20 weight percent.

Emulsions/Emulsifiers

A stable emulsion is a mixture of two immiscible liquids, i.e. liquidsthat are not mutually soluble, but which can form a fluid in which verysmall droplets of one component are stably dispersed throughout theother liquid, giving the mixture the appearance of a homogeneous fluid.Emulsions can include particulate materials and materials which aresolid or solid-like at room temperature, but which will liquefy athigher temperatures used during formation of the emulsion. The presenceof an emulsifier enhances the ability of one of the immiscible liquidsto remain in a continuous form, while allowing the other immiscibleliquid to remain in a dispersed droplet form. Thus, one function of anemulsifier, a stabilizing compound, is to assist in the production of astable emulsion. A secondary function of emulsifiers is to provide athickening or "bodying" to an emulsion. Typically, emulsifiers aremolecules with non-polar and polar parts that are able to reside at theinterface of the two immiscible liquids. As used herein in reference tothe emulsifiers, the term "HLB value" means the hydrophilic/lipophilicbalance. The HLB value has been used by those skilled in the emulsionart as an approximate (but certainly not infallible) guide to selectingspecific emulsifiers useful for preparing the various types ofemulsions. In general, the higher HLB (i.e., over about 7) valuespredict usefulness of an emulsifier for producing oil-in-wateremulsions.

An oil-in-water (o/w) emulsion is a mixture where water-insolubledroplets (the discontinuous phase) are dispersed in a continuous aqueousphase. A water-in-oil (w/o) emulsion is a mixture where water droplets(the discontinuous phase) are dispersed in a continuous oily phase.Preferably the composition of the present invention is an oil-in-wateremulsion where the oil-soluble actives are dispersed in the oil phase,prior to mixture with the water phase. The type of emulsion,oil-in-water (o/w) or water-in-oil (w/o), formed is sometimes determinedby the volume ratio of the two liquids, provided the ratio issufficiently high. For example, with 95% water and 5% oil phases (an o/wphase ratio of 19), the emulsion likely will become o/w. For moderateratios (<3), the type of emulsion is decided by several factors, such asorder of addition or type of emulsifier. One liquid slowly added to asecond liquid with vigorous agitation usually results in the secondliquid being the continuous phase. Another factor is preferredsolubility of the emulsifier, the phase in which the emulsifier issoluble most probably is continuous.

More complex emulsions such as double emulsions are formed where anemulsion is dispersed in a continuous phase. For example, in an oilin-water-in oil (o/w/o) emulsion, the water in a continuous water phasecontaining dispersed oil droplets is itself dispersed in a continuousoil phase. Similarly, in a water-in oil-in water (w/o/w) emulsion, theoil in a continuous phase containing dispersed water droplets is itselfdispersed in a continuous water phase. These more complex emulsions,however, are not commonly used for products such as sunscreens.

Emulsifiers useful in the present invention may be anionic, cationic ornon-ionic, and either liquid or solid at room temperature. Emulsifierswhich are salts may be formed in-situ when their constituents (such asstearic acid and triethanolamine, which form TEA-stearate) are presenttogether in the formulation. Suitable emulsifiers include, withoutlimitation, sorbitan esters such as sorbitan isostearate available asCrill 6, tradename of Croda Inc. of New York, N. Y. U.S.A.;polyglyceryl-3 distearate available as Cremophor GS-32, tradename ofBASF, Parsippany, N.J. U.S.A.; carbomer, which is a homopolymer ofacrylic acid crosslinked with an allyl ether of sucrose, available asCarbopol 941, tradename of B.F. Goodrich, Cleveland, Ohio U.S.A. Otheruseful emulsifiers include ceteareth-15, cetyl alcohol, cetyl phosphate,dimethicone copolyol phosphate, glyceryl isostearate, hydrogenatedlecithin, laureth-12, PEG-20 distearate, PEG-8 oleate, PEG-40 sorbitandiisostearate, polyglyceryl-10 distearate, polysorbate 20, polysorbate80, PPG-7 lauryl ether, sodium laureth sulfate, sorbitan sesquioleateand acrylates/C₁₀₋₃₀ alkyl acrylate crosspolymer; these are onlyrepresentatives from some of the useful emulsifier chemical classes.

During preparation of the emulsion, an acid or a base may be added toadjust the pH of one or more ingredients, e.g. to adjust the viscosityof a polymeric thickener, prior to its inclusion in the sunscreencomposition. For example, triethanolamine, a base, can be used toincrease the pH of the water phase and consequently modify the desiredviscosity of the emulsion. The sunscreen typically has a pH of about 4to about 9, preferably from about 6.5 to about 8.5; more preferably thepH of the sunscreen is approximately neutral, i.e. about 7.

Conveniently, one or more emulsifiers can be used in the compositions ofthe present invention in amounts ranging from about 0.05 to about 20weight percent of emulsion, preferably from about 0.1 to about 15percent, more preferably from about 5 to about 10 percent.

Water

Water is employed in amounts effective to form the emulsion. It ispreferred to use water which has been subjected to purificationprocedures such as deionization or reverse osmosis, to minimizeformulation inconsistencies due to dissolved solids in the water. Theamount of water in the emulsion or composition can range from about 2 to95 weight percent, preferably from 40 to 85 percent.

Emollients

An emollient is an oleaginous or oily substance which helps to smoothand soften the skin, and may also reduce its roughness, cracking orirritation. Typical suitable emollients include mineral oil having aviscosity in the range of 50 to 500 centipoise (cps), lanolin oil,coconut oil, cocoa butter, olive oil, almond oil, macadamia nut oil,aloe extracts such as aloe vera lipoquinone, synthetic jojoba oils,natural sonora jojoba oils, safflower oil, corn oil, liquid lanolin,cottonseed oil and peanut oil.

Other suitable emollients include, without limitation, squalane, castoroil, polybutene, odorless mineral spirits, sweet almond oil, avocadooil, calophyllum oil, ricin oil, vitamin E acetate, olive oil, siliconeoils such as dimethylopolysiloxane and cyclomethicone, linolenicalcohol, oleyl alcohol, the oil of cereal germs such as the oil of wheatgerm, isopropyl palmitate, octyl palmitate which is commerciallyavailable as Lexol EHP, tradename of Inolex Co. of Philadelphia, Pa.U.S.A., isopropyl myristate, hexadecyl stearate, butyl stearate, decyloleate, acetyl glycerides, the octanoates and benzoates of (C₁₂ -C₁₅)alcohols, the octanoates and decanoates of alcohols and polyalcoholssuch as those of glycol and glycerol, ricinoleates and esters ofalcohols and polyalcohols such as isopropyl adipate, hexyl laurate andoctyl dodecanoate.

Other suitable emollients which are solids or semi-solids at ambienttemperatures may be used. Such solid or semi-solid cosmetic emollientsinclude hydrogenated lanolin, hydroxylated lanolin, acetylated lanolin,petrolatum, isopropyl lanolate, butyl myristate, cetyl myristate,myristyl myristate, myristyl lactate, cetyl alcohol, isostearyl alcoholand isocetyl lanolate. One or more emollients can optionally be includedin the sunscreen emulsion in an amount ranging from about 10 to about 50weight percent, preferably about 20 to about 40 percent.

Humectants

A humectant is a moistening agent that promotes retention of water dueto its hygroscopic properties. Suitable humectants include glycerin,polymeric glycols such as polyethylene glycol and polypropylene glycol,mannitol and sorbitol. One or more humectants can optionally be includedin the in the sunscreen in amounts from about 1 to 10 weight percent.

Dry-Feel Modifier

A dry-feel modifier is an agent which when added to a emulsion, impartsa "dry feel" to the skin when the emulsion dries. Dry-feel modifiers mayalso reduce sunscreen migration on the skin. Dry feel modifiers caninclude starches, talc, kaolin, chalk, zinc oxide, silicone fluids,inorganic salts such as barium sulfate and sodium chloride, C₆ to C₁₂alcohols such as octanol; sulfonated oils; surface treated silica,precipitated silica, fumed silica such as Aerosil® available from theDegussa Inc. of New York, N.Y. U.S.A. or mixtures thereof; dimethicone,a mixture of mixture of methylated linear siloxane polymers, availableas DC200 fluid, tradename of Dow Corning, Midland, Mich. U.S.A. One ormore dry-feel modifiers can optionally be included in the sunscreen inamounts ranging from 0.01 to about 20 weight percent, preferably fromabout 0.5 to about 6 weight percent.

Waterproofing Agents

A waterproofing agent is a hydrophobic material that imparts filmforming and waterproofing characteristics to an emulsion. Typicalsuitable waterproofing agents include copolymers derived frompolymerization of octadecene-1 and maleic anhydride in accordance withthe procedures in U.S. Pat. No. 3,860,700 and Re. 28,475. A preferredwaterproofing agent is a polyanhydride resin, also known as PA-18,tradename of the Chevron Chemicals Co., San Francisco, Calif. U.S.A.Another preferred waterproofing agent is a copolymer of vinylpyrollidone and eicosene monomers such as Ganex Polymer, tradename ofISP Inc. of Wayne, N.J. U.S.A.

The waterproofing agent is preferably used in amounts effective tomaintain the sunscreen effectiveness on the skin following exposure tocirculating water for at least 80 minutes, using the proceduresdescribed by the U.S. Food and Drug Administration in "Sunscreen DrugProducts for OTC Human Use," Federal Register, Vol. 43, Aug. 25, 1978,Part 2, pp. 38206-38269. One or more waterproofing agents can optionallybe included in the sunscreen composition in an amount ranging from about0.01 to about 10 weight percent, preferably about 1 to about 10 percent.

Antimicrobial Preservative

An antimicrobial preservative is a substance or preparation whichdestroys, or prevents or inhibits the proliferation of, microorganismsin the sunscreen composition, and which may also offer protection fromoxidation. Preservatives are frequently used to make self-sterilizing,aqueous based products such as emulsions. This is done to prevent thedevelopment of microorganisms that may be in the product from growingduring manufacturing and distribution of the product and during use byconsumers, who may further inadvertently contaminate the products duringnormal use. Among the numerous typical preservatives are the lower alkylesters of para-hydroxybenzoates (parabens) especially, methylparaben,propylparaben, isobutylparaben and mixtures thereof, imidazolidinylurea, benzyl alcohol and benzoic acid. One or more antimicrobialpreservatives can optionally be included in the sunscreen composition inan amount ranging from about 0.001 to about 10 weight percent,preferably about 0.05 to about 2 percent.

Antioxidants

An antioxidant is a natural or synthetic substance added to theformulation to protect from or delay its deterioration due to the actionof oxygen in the air (oxidation). Anti-oxidants prevent oxidativedeterioration which may lead to the generation of rancidity andnonenyzymatic browning reaction products. Typical suitable antioxidantsinclude propyl, octyl and dodecyl esters of gallic acid, butylatedhydroxyanisole (BHA, usually purchased as a mixture of ortho and metaisomers), butylated hydroxytoluene (BHT), nordihydroguaiaretic acid,vitamin E, vitamin E acetate, vitamin C and alkylated parabens such asmethylparaben and propylparaben. One or more antioxidants can optionallybe included in the sunscreen composition in an amount ranging from about0.001 to about 5 weight percent, preferably about 0.05 to about 2percent.

Chelating Agents

Chelating agents are substances used to chelate or bind metallic ions,such as with a certain heterocyclic ring structure so that the ion isheld by chemical bonds from each of the participating rings. Suitablechelating agents include ethylene diaminetetraacetic acid (EDTA), EDTAdisodium, calcium disodium edetate, EDTA trisodium, EDTA tetrasodium andEDTA dipotassium. One or more chelating agents can optionally beincluded in the sunscreen in amounts ranging from about 0.001 to about0.1 weight percent.

Fragrances

Fragrances are aromatic substances which can impart an aestheticallypleasing aroma to the sunscreen composition. Typical fragrances includearomatic materials extracted from botanical sources (i.e. rose petals,gardenia blossoms, jasmine flowers, etc.) which can be used alone or inany combination to create essential oils. Alternatively, alcoholicextracts may be prepared for compounding fragrances. However, due to therelatively high costs of obtaining fragrances from natural substances,the modern trend is to use synthetically prepared fragrances,particularly in high-volume products. One or more fragrances canoptionally be included in the sunscreen composition in an amount rangingfrom about 0.001 to about 10 weight percent, preferably about 0.05 toabout 5 percent.

Insect Repellents

Insect repelling components are desirable in sunscreening emulsions,since the emulsions are normally used primarily by persons engaged inoutdoor activities. The most widely used active agent for personal careproducts is N,N-Diethyl-m-toluamide, frequently called "DEET" andavailable in the form of a concentrate containing at least about 95percent DEET. Other synthetic chemical repellents include dimethylphthalate, ethyl hexanediol, indalone, di-n-propylisocinchoronate,bicycloheptene, dicarboximide and tetrahydrofuraldehyde. Certainplant-derived materials also have insect repellent activity, includingcitronella oil and other sources of citronella (including lemon grassoil), limonene, rosemary oil and eucalyptus oil. Choice of an insectrepellent for incorporation into the sunscreen emulsion will frequentlybe influenced by the odor of the repellent. The amount of repellentagent used will depend upon the choice of agent; DEET is useful at highconcentrations, such as up to about 15 percent or more, while some ofthe plant-derived substances are typically used in much lower amounts,such as 0.1 percent or less.

Dispensers

The sunscreen emulsions of the present invention containing thedisappearing color indicator can be stored or dispensed in any containersuitable for convenient delivery, i.e. pouring or spraying. Suchcontainers can include but are not limited to jars, bottles, lotion pumpbottles, pump spray bottles and pressurized aerosols.

Application Method

To achieve the maximum possible uniformity of application to the skin,the sunscreen lotions of the invention should be spread onto exposedskin in sufficient amounts to yield a distinctly visible uniform layerof colored lotion. After it is visually verified that the desiredcoverage has been obtained, the lotion should be rubbed into the skin tocause the visible color to disappear. As with most sunscreen products,it is recommended that the sunscreen be applied shortly (e.g., 15minutes) prior to commencing exposure to ultraviolet radiation; thispermits the emulsion to break apart, due to evaporation of its containedwater, and frees the active ingredients from the formulation.

The visualization and disappearance of the sunscreen on the skin can beevaluated using visual, chromatographic and pantone matching systems.

To evaluate the color indicator on the skin, it is helpful to have anobjective, instrumental measurement of colors and intensities.Accordingly, a method has been developed using the Minolta Chroma MeterModel CR-200, which uses reflected light from a surface and givesresults in terms of the CIE (International Commission on Illumination)tristimulus values. These values are subsequently transformedmathematically into the L* a* b* color space, wherein the magnitudes ofchanges in hue and intensity of color correspond closely with thoseperceived by the human eye.

L*, being achromatic, ranges from black (L*=0) to white (L*=100); thisterm is called "metric lightness" and is a measure of how light or darka color is, relative to a matching shade of gray. Hue is measured interms of the chromaticity coordinates a* and b*, where a* indicatesredness (a*>0) and b* indicates yellowness (b*>0). The values of a* andb* can be plotted with a* as the x-axis and b* as the y axis, to givequantitative color information: "metric chroma" is the length of a linefrom the origin (a*=0b , b*=0) to the point of a sample reading, while"metric hue angle" is the angle between the a* axis and the metricchroma line. Metric chroma indicates the strength of a color response(i.e., the extent to which a color differs from its matching shade ofgray). Metric hue angle quantifies hue in degrees, with larger valuesindicating more yellow hues and smaller values indicating more red (orless yellow) hues.

The meter can be used to measure a base line skin tone as well asresidual color left on the skin after "rub out" with a number ofsubjects, to establish a target for disappearance of color applied tothe skin.

Definitions and suppliers of many of the ingredients mentioned above orused in the following illustrative examples may be found in J. M.Nikitakis et al., Eds., CTFA International Cosmetic IngredientDictionary, Fourth Ed., The Cosmetic, Toiletry and FragranceAssociation, 1101 17th Street NW, Washington, D.C. 20036 U.S.A., 1991.This dictionary lists the chemical and adopted names, and commercialdesignations, of many of the substances mentioned herein.

The following examples are provided solely to further illustrate theinvention, and are not intended to limit the scope of the invention asit is defined by the appended claims. Percentages given throughout thisspecification and claims indicate, unless the context clearly dictatesotherwise, percent by weight.

EXAMPLE 1

A kilogram batch of sunscreen lotion, having an SPF value of 30 and aviolet color, is prepared according to the invention using the followingcomponents:

    ______________________________________                                        Component              Grams                                                  ______________________________________                                        Part A                                                                        Stearic acid, NF       20                                                     Sorbitan isostearate   40                                                     Octyl p-methoxycinnamate                                                                             75                                                     Homomenthyl salicylate 80                                                     Benzophenone-3         60                                                     Octyl salicylate       15                                                     Jojoba oil             0.5                                                    Aloe vera lipoquinone  0.5                                                    Propylparaben          1                                                      Polyglyceryl-3 distearate                                                                            30                                                     D & C Violet #2        0.5                                                    Part B                                                                        Octadecene/maleic anhydride copolymer                                                                30                                                     Dimethicone            4                                                      Vitamin E acetate      1                                                      Part C                                                                        Octyl salicylate       35                                                     Barium sulfate         17.5                                                   Part D                                                                        Water                  190                                                    Carbomer 941           0.25                                                   Part E                                                                        Water                  247.15                                                 Sorbitol 70% aqueous solution                                                                        50                                                     Triethanolamine        22.5                                                   Methylparaben          2                                                      Disodium EDTA          0.1                                                    Part F                                                                        Benzyl alcohol         10                                                     Fragrance              6                                                      Part G                                                                        Water                  62                                                     ______________________________________                                    

The following procedure is used to prepare the lotion: (1) combine thePart A components and, with stirring, heat the mixture to about 82-85°C., then add the octadecene/ maleic acid copolymer from Part B and stirto dissolve; (2) cool the step 1 mixture to about 77-79° C. and add theremaining Part B components with continuous mixing; (3) in anothervessel, sprinkle the barium sulfate onto the well agitated octylsalicylate of Part C, mix for 30 minutes and then combine thisdispersion with the mixture of step 2; (4) in a vessel sized to containthe entire production batch, combine the Part D components and mix toform a smooth, lump-free mixture; (5) sequentially add the components ofPart E to the step 4 mixture, reserving the triethanolamine, heat toabout 77-82° C. with continuous mixing, then add the triethanolaminewhen a clear solution is achieved; (6) add the Part G component to thesolution of step 5, with mixing; (7) add the oil phase from step 3 tothe aqueous phase from step 6 with vigorous mixing, then, with normalmixing, begin cooling the formed emulsion to ambient temperature; and(8) as the temperature falls through about 49° C. add the Part Fcomponents and sufficient water to compensate for any evaporative losseswhich occurred during the procedure.

The violet lotion is highly visible as it is being spread onto the skin,but substantially disappears as the formulation is rubbed into the skin.

EXAMPLE 2

A kilogram batch of sunscreen lotion, having an SPF value of 30 and agreen color, is prepared according to the invention using the followingcomponents and the procedure of the preceding example:

    ______________________________________                                        Component              Grams                                                  ______________________________________                                        Part A                                                                        Stearic acid, NF       20                                                     Sorbitan isostearate   40                                                     Octyl p-methoxycinnamate                                                                             75                                                     Homomenthyl salicylate 80                                                     Benzophenone-3         60                                                     Octyl salicylate       15                                                     Jojoba oil             0.5                                                    AIoe vera lipoquinone  0.5                                                    Propylparaben          1                                                      Polyglyceryl-3 distearate                                                                            30                                                     D & C Green #6         1                                                      Part B                                                                        Octadecene/maleic anhydride copolymer                                                                30                                                     Dimethicone            4                                                      Vitamin E acetate      1                                                      Part C                                                                        Octyl salicylate       35                                                     Barium sulfate         17.5                                                   Part D                                                                        Water                  190                                                    Carbomer 941           0.25                                                   Part E                                                                        Water                  246.65                                                 Sorbitol, 70% aqueous solution                                                                       50                                                     Triethanolamine        22.5                                                   Methylparaben          2                                                      Disodium EDTA          0.1                                                    Part F                                                                        Benzyl alcohol         10                                                     Fragrance              6                                                      Part G                                                                        Water                  62                                                     ______________________________________                                    

The green lotion is highly visible as it is being spread onto the skin,but substantially disappears as the formulation is rubbed into the skin.

What is claimed is:
 1. A colored sunscreen emulsion comprising:a) atleast one oil-soluble dye that imparts a color other than white to thesunscreen emulsion, to render the emulsion highly visible while it isbeing spread onto the skin, but which color substantially disappearswhen the spread emulsion is rubbed into the skin; b) at least onesunscreen active agent in an amount effective to protect skin againstthe actinic radiation of the sun; c) at least one emulsifier; and d)sufficient water to form the colored emulsion.
 2. The colored sunscreenemulsion of claim 1, wherein the dye is a D&C color or a noncertifiedequivalent thereof, or a mixture of two or more D&C colors ornoncertified equivalents.
 3. The colored sunscreen emulsion of claim 1,wherein the dye imparts a blue, purple, violet, yellow, green or aquacolor to the sunscreen emulsion.
 4. The colored sunscreen of claim 1,wherein the dye comprises one or more members selected from the groupconsisting of D&C Violet #2, D&C Green #6, D&C Yellow #11, D&C Red #17and noncertified equivalents thereof.
 5. The colored sunscreen of claim1, wherein the dye comprises D&C Violet #2 or a noncertified equivalentthereof.
 6. The colored sunscreen of claim 1, wherein the dye comprisesD&C Green #6 or a noncertified equivalent thereof.
 7. The coloredsunscreen emulsion of claim 1, wherein the amount of the dye ranges fromabout 0.0005 to about 0.5 weight percent of the emulsion.
 8. The coloredsunscreen emulsion of claim 1, wherein the amount of the dye ranges fromabout 0.002 to about 0.2 weight percent of the emulsion.
 9. The coloredsunscreen emulsion of claim 1, wherein the amount of the dye ranges fromabout 0.01 to about 0.1 weight percent of the emulsion.
 10. The coloredsunscreen emulsion of claim 1, which is an oil-in-water emulsion (o/w).11. The colored sunscreen emulsion of claim 1, which is awater-in-oil-in water emulsion (w/o/w).
 12. The colored sunscreenemulsion of claim 1 having a pH about 4 to about
 9. 13. The coloredsunscreen emulsion of claim 1 having a pH about 6.5 to about 7.5. 14.The colored sunscreen emulsion of claim 1, further comprising one ormore emollients.
 15. The colored sunscreen emulsion of claim 1, furthercomprising one or more waterproofing agents.
 16. The colored sunscreenemulsion of claim 1, further comprising one or more antimicrobialpreservatives.
 17. The colored sunscreen emulsion of claim 1, furthercomprising one or more dry-feel modifiers.
 18. The colored sunscreenemulsion of claim 1, further comprising one or more fragrances.
 19. Thecolored sunscreen emulsion of claim 1, further comprising one or moreinsect repellents.
 20. A method for protecting the skin against damagefrom exposure to ultraviolet radiation, comprising topically applying tothe skin the colored sunscreen emulsion of claim
 1. 21. A coloredsunscreen emulsion comprising:a) about 0.0005 to about 0.5 weightpercent of at least one oil-soluble dye selected from the groupconsisting of D&C Violet #2, D&C Green #6, D&C Yellow #11, D&C Red #17,noncertified equivalents thereof and mixtures of any two or more of theforegoing, in an amount sufficient to impart a color other than white tothe sunscreen emulsion to render the emulsion highly visible while it isbeing spread onto the skin, but which color substantially disappearswhen the spread emulsion is rubbed into the skin; b) at least onesunscreen active agent in an amount effective to protect skin againstthe actinic radiation of the sun; c) at least one emulsifier; and d)sufficient water to form the colored emulsion.